Since Puppet stopped passing environment variables down to subprocesses (like, say, `apt-get install`), I've occasionally run into problems where a package postinst script relies on something in the environment. The PostgreSQL package (on Ubuntu 12.04 at least) is one such beast. It relies on the current locale (gleamed from the environment) to …

config.pp

class postgresql::server::config {
  exec {
    'postgresql-drop-cluster':
      command => '/usr/bin/pg_dropcluster --stop 9.1 main',
      onlyif  => "/usr/bin/psql -c '\\l+' |awk '/template0/ { print \$5 }' |grep 'SQL_ASCII'",
      user    => postgres,
      notify  => Exec['postgresql-create-cluster'];

    'postgresql-create-cluster':
      command     => '/usr/bin/pg_createcluster --locale=en_GB.UTF-8 9.1 main',
      user        => postgres,
      refreshonly => true,
      before      => [ File['/etc/postgresql/9.1/main/postgresql.conf'], File['/etc/postgresql/9.1/main/pg_hba.conf'] ];
  }
}